The present invention relates to a manufacturing method of a semiconductor device, a semiconductor device, a connector for a narrow pitch, an electrostatic actuator including this connector for a narrow pitch, a piezoelectric actuator, a micromachine, a liquid crystal panel, and an ink jet head using these electrostatic actuator and piezoelectric actuator, an ink jet printer on which these ink jet heads are mounted, and electronic appliances.
Conventionally, known is a method in which an insulating layer is formed on the surface of single crystal silicon wafer (hereinafter to be referred to as silicon wafer) and the upper surface of this insulating layer undergoes the CVD method (or spattering) and etching so that wirings, etc. are formed, and thus a semiconductor device is manufactured.
FIG. 23 is a plan view of a silicon wafer in which a semiconductor device has been formed, and FIG. 24 is a sectional view along a line Axe2x80x94A in FIG. 23 showing the main portion thereof which has been enlarged.
On the surface of a silicon wafer 1, as shown in FIG. 23, a number of semiconductor devices 3 are formed and sandwiching dicing lines 5 shaping an lattice. The semiconductor device 3 shown herein has an IC7 formed on the insulating layer 4 of the silicon wafer 1 and a micro-wiring 9 drawn out from this IC7.
Thus, a number of semiconductor devices 3 formed on the surface of the silicon wafer 1 are, as shown in FIG. 25, cut out into chips by a cutter 11 such as diamond blade or rotating thin whetstone called dicing blade along the dicing lines 5.
The semiconductor devices 3 cut out into chips are brought into electrical and mechanical connection with an external substrate via a flexible substrate (connector) made of, for example, polyimide. Incidentally, connection between a terminal electrode of the semiconductor device 3 and an electrode of the flexible substrate is implemented by pressuring and heating by way of an anisotropy conductive adhesive containing conductive particles, etc.
However, the semiconductor substrate to be manufactured as described above gives rise to following problems.
FIGS. 26(A) and (B) are enlarged views showing the main portions of the semiconductor device 3 cut out from the silicon wafer 1. As shown in FIG. 26(A), cutting out the semiconductor device 3 will cause the single crystal surface of silicon to be exposed on an end surface 1a along the dicing line. In addition, an insulating layer 4 formed on the surface of the silicon wafer 1 has thickness no more than around 5000 to 20000 angstroms. Therefore, there was a possibility that a conductive dust 13 floating in the air comes into attachment so as to span the insulating layer 4 as shown in FIG. 26(A) so that the quasi-micro wiring 9 and the end surface la are short-circuited (edge short).
In addition, there was also a possibility that the soldering material or conductive adhesive 15 used for connection between IC7 and micro-wiring 9 starts flowing out to reach the end surface 1a as shown in FIG. 26(B) so that short circuit (edge short) could take place.
In the surface of the semiconductor device 3, the portions other than the micro-wiring 9 are covered by the insulating layer 4. Thus, there was also a possibility that in the case where static electricity takes place in the air, static electricity is charged into the micro-wiring 9 of the semiconductor device 3, which is repeated so that the micro-wiring 9 was fused.
Incidentally, the semiconductor device includes for example a micromachine such as a piezoelectric actuator, electrostatic actuator, etc., a micromachine, etc., which is configured by connecting a semiconductor device in which an IC is disposed on a narrow pitch connector, and liquid crystal panel, etc.
An object of the present invention is to provide a manufacturing method of semiconductor devices in that short circuit will not take place due to dusts floating in the air, micromachines such as semiconductor device, narrow pitch connectors, electrostatic actuators, piezoelectric actuators, or the like, ink jet heads including them, ink jet printers, liquid crystal panels, and electronic appliances.
(1) A manufacturing method of semiconductor devices related to one aspect of the present invention is a manufacturing method of semiconductor devices in which a silicon wafer undergoes dicing to manufacture plural semiconductor devices, characterized in that, a groove covered by an insulating layer and spanning a dicing line is formed in the above described silicon wafer, and the above described silicon wafer undergoes dicing along the above described dicing line.
According to the above described manufacturing method, an insulating layer is formed on an outer periphery surface of a semiconductor device. Therefore, conductive dusts, which could adhere to the periphery section of the semiconductor device, will be blocked by the insulating layer formed on the outer periphery surface and will not reach the silicon crystal face. Therefore, short circuit will not take place.
In addition, soldering material or conductive adhesive to mount elements could flow out, but will be blocked by the insulating layer formed on the outer periphery surface and will not reach the silicon crystal face. Therefore, in this case too, short circuit will not take place.
(2) The manufacturing method of semiconductor device related to another aspect of the present invention is, in the above described (1), characterized in that a metal film is formed on an insulating layer after the insulating layer is formed on the bottom surface of the above described groove.
With such an arrangement, the static electricity in the air is charged into this metal film so that the semiconductor elements or wiring sections can be prevented from being charged with the static electricity. In addition, if a person who is charged with static electricity or a metal which is charged with static electricity comes into contact with a semiconductor device, the transferred static electricity is charged into the metal film so that the semiconductor elements or the wiring section can be prevented from being charged with the static electricity.
(3) A manufacturing method of the semiconductor device related to another aspect of the present invention is, in the above described (2), characterized in that the above described metal film is brought into conduction to a crystal face of the above described silicon wafer.
By such an arrangement, if a device grasping the semiconductor substrate is grounded in an assembly line, or the crystal face is grounded after assembly, the metal film can be charged with static electricity and the charged static electricity can be caused to flow, so that bad influence by static electricity can be surely prevented.
(4) A manufacturing method of the semiconductor device related to another aspect of the present invention is, in the above described (1) to (3), characterized in that the crystal face on the surface of the above described silicon wafer is the (110)-plane and the groove is formed by implementing anisotropy etching on the (110)-plane.
By an arrangement in which the (110)-plane undergoes anisotropy etching, the depth of the groove to be formed can be set freely. Thereby, the groove can be formed to have a depth corresponding to the size (length) of the dusts expected to adhere, or viscosity and quantity of the soldering material or conductive adhesive agent to be used for mounting elements.
(5) A manufacturing method of the semiconductor device related to another aspect of the present invention is, in the above described (1) to (3), characterized in that the crystal face on the surface of the above described silicon wafer is the (100)-plane, and the groove is formed by implementing anisotropy etching on the (100)-plane.
If the (100)-plane is arranged to undergo anisotropy etching, the groove can be V-shaped. Therefore, when a semiconductor device is cut out into a chip, an inclined insulating layer will be formed in the circumference of the semiconductor device so that dusts and dirt generated at the time of dicing can be easily removed.
(6) The semiconductor device related to another aspect of the present invention is characterized in that an insulating layer is formed on the outer periphery surface of a substrate in which elements are formed.
Since the insulating layer is formed on an outer periphery surface of a semiconductor device, a conductive dust, which happens to adhere to the circumference of the semiconductor device, will be blocked by the insulating layer formed on the outer periphery surface and will not reach the substrate surface. Therefore, no short circuit will take place.
In addition, soldering material or conductive adhesive to mount elements could flow out, but will be blocked by the insulating layer formed on the outer periphery surface and will not reach the substrate surface. Accordingly, also in this case no short circuit will take place.
(7) The semiconductor device related to another aspect of the present invention is, in the above described (6), characterized in that an inclined section is formed on the above described outer periphery surface.
Since the inclined section is formed in the circumference of the semiconductor device, the dusts and dirt that adhere to the periphery section of the semiconductor device can be easily removed.
(8) The semiconductor device related to another aspect of the present invention is, in the above described (6), characterized in that a step section is formed on the outer periphery surface.
(9) The narrow pitch connector related to another aspect of the present invention is a connector for a narrow pitch comprising a substrate on which first terminal electrodes, second terminal electrodes and wiring electrically connecting the first terminal electrodes with the second terminal electrodes are formed, the wiring having a function of making conversion from the pitch of the first terminal electrodes to the pitch of the second terminal electrodes and is characterized in that an insulating layer is formed on the outer periphery surface of the substrate.
Since the insulating layer is formed on the outer periphery surface of the substrate of the narrow pitch connector, a conductive dust, which happens to adhere to the circumference of the substrate, will be blocked by the insulating layer formed on the outer periphery surface and will not reach the crystal face. Therefore, no short circuit will take place.
In addition, soldering material or conductive adhesive used at the time when the narrow pitch connector is brought into junction with a connection object or outside of the substrate could flow out, but will be blocked by the insulating layer and will not reach the crystal face. Accordingly, also in this case no short circuit will take place.
(10) The narrow pitch connector related to another aspect of the present invention is, in the above described (9), characterized in that the outer periphery surface has an inclined section.
Since the inclined section is formed on the outer periphery surface of the substrate of the narrow pitch connector, the dusts and dirt that adhere to the narrow pitch connector can be easily removed.
(11) The narrow pitch connector related to another aspect of the present invention is, in the above described (9), characterized in that the outer periphery surface has a step section.
(12) The narrow pitch connector related to another aspect of the present invention is, in the above described (9) to (11), characterized in that a metal film is formed on the insulating layer.
With such an arrangement, the static electricity in the air is charged into the metal film so that the micro-wiring section of the narrow pitch connector can be prevented from being charged with the static electricity. In addition, even in a case where a person who is charged with static electricity or a metal which is charged with static electricity comes into contact with a semiconductor device, the transferred static electricity is charged into the metal film so that the semiconductor elements or the wiring section can be prevented from being charged with the static electricity.
(13) The narrow pitch connector related to another aspect of the present invention is, in the above described (12), characterized in that the metal film is brought into conduction to the substrate.
By such an arrangement, if a device grasping the narrow pitch connector is grounded in an assembly line, or the crystal substrate is grounded after assembly, the metal film can be charged with static electricity and the charged static electricity can be caused to flow, so that bad influence by static electricity can be surely prevented.
(14) The narrow pitch connector related to another aspect of the present invention is, in the above described (9) to (13), characterized in that the connector has characteristics that the thermal expansion coefficient of the substrate is approximately equivalent to the thermal expansion coefficient of a connection object to be connected, or smaller than the thermal expansion coefficient of the connection object.
Thus, with the thermal expansion coefficient of the substrate being made approximately equivalent to the thermal expansion coefficient of the connection object, when the terminal electrodes are connected by being subjected to pressure and heat, deviation of relative positions between the terminal electrodes to be connected can be controlled to minimum.
In addition, in the case where the thermal expansion coefficient of the substrate is made smaller than the thermal expansion coefficient of the connection object, the substrate is arranged to be connected at a higher temperature than the connection object so that a similar effect is obtainable.
(15) The narrow pitch connector related to another aspect of the present invention is, in the above described (9) to (14), characterized in that the substrate is formed of single crystal silicon.
The substrate formed of single crystal silicon can improve radiation effects and prevent increase in resistant value due to temperature rise.
(16) The narrow pitch connector related to another aspect of the present invention is, in the above described (15), characterized in that the crystal face of the single crystal silicon is (100)-plane.
With the crystal face of single crystal silicon being (100)-plane, if the surface undergoes anisotropy etching, a V-groove having an angle of 54.74 degree to the surface can be formed. Incidentally, the depth of the V groove can be accurately controlled by the width of the window (for example made of SiO2 film) set on the (100)-plane.
(17) The narrow pitch connector related to another aspect of the present invention is, in the above described (15), characterized in that the crystal face of the single crystal silicon is (110)-plane.
With the crystal face of single crystal silicon being (110)-plane, if the surface undergoes anisotropy etching, a groove having a rectangular section can be formed. In this case, regardless of the groove width, a groove having predetermined depth can be formed.
(18) A micromachine related to another aspect of the present invention, including an active mechanism and a first substrate having first terminal electrodes is characterized in that the micromachine further includes a second substrate having second terminal electrodes to be electrically connected to the first terminal electrodes, the second substrate further has third terminal electrodes and wiring electrically connecting the second terminal electrodes with the third terminal electrodes, the wiring has a function of making conversion from the pitch of the second terminal electrodes to the pitch of the third terminal electrodes, and the outer periphery surface of the second substrate has an insulating layer formed thereon.
(19) A piezoelectric actuator related to another aspect of the present invention, including a piezoelectric element and a first substrate having first terminal electrodes, is characterized in that the piezoelectric actuator further includes a second substrate having second terminal electrodes to be electrically connected to the first terminal electrodes, the second substrate further has third terminal electrodes and wiring electrically connecting the second terminal electrodes with the third terminal electrodes, the wiring has a function of making conversion from the pitch of the second terminal electrodes to the pitch of the third terminal electrodes, and the outer periphery surface of the second substrate has an insulating layer formed thereon.
(20) An electrostatic actuator related to another aspect of the present invention, including an electrostatic oscillator and a first substrate having first terminal electrodes, is characterized in that the electrostatic actuator further includes a second substrate having second terminal electrodes to be electrically connected to the first terminal electrodes, the second substrate further has third terminal electrodes and wiring connecting the second terminal electrodes with the third terminal electrodes, the wiring has a function of making conversion from the pitch of the second terminal electrodes to the pitch of the third terminal electrodes, and the outer periphery surface of the second substrate has an insulating layer formed thereon.
(21) An ink jet head related to another aspect of the present invention, including a piezoelectric element and a first substrate having first terminal electrodes, to spill out ink drops by the piezoelectric element, is characterized in that the ink jet head further includes second substrate having second terminal electrodes to be electrically connected to the first terminal electrodes, the second substrate further has third terminal electrodes and wiring electrically connecting the second terminal electrodes with the third terminal electrodes, the wiring has a function of making conversion from the pitch of the second terminal electrodes to the pitch of the third terminal electrodes, and the outer periphery surface of the second substrate has an insulating layer formed thereon.
(22) An ink jet head related to another aspect of the present invention, including an electrostatic oscillator and a first substrate having first terminal electrodes, to spill out ink drops by the electrostatic oscillator, is characterized in that the ink jet head further includes a second substrate having second terminal electrodes to be electrically connected to the first terminal electrodes, and the second substrate further has third terminal electrodes and wiring electrically connecting the second terminal electrodes with the third terminal electrodes, the wiring has a function of making conversion from the pitch of the second terminal electrodes to the pitch of the third terminal electrodes, and the outer periphery surface of the second substrate has an insulating layer formed thereon.
(23) An ink jet printer related to another aspect of the present invention, comprising an ink jet head including a piezoelectric element and a first substrate having first terminal electrodes, is characterized in that the ink jet head further includes a second substrate having second terminal electrodes to be electrically connected to the first terminal electrodes, the second substrate further has third terminal electrodes and wiring electrically connecting the second terminal electrodes with the third terminal electrodes, the wiring has a function of making conversion from the pitch of the second terminal electrodes to the pitch of the third terminal electrodes, and the outer periphery surface of the second substrate has an insulating layer formed thereon.
(24) An ink jet printer related to another aspect of the present invention, comprising an ink jet head including an electrostatic oscillator and a first substrate having first terminal electrodes is characterized in that the ink jet head further includes a second substrate having second terminal electrodes to be electrically connecting to the first terminal electrodes, the second substrate further has third terminal electrodes and wiring electrically connecting the second terminal electrodes with the third terminal electrodes, the wiring has a function of making conversion from the pitch of the second terminal electrodes to the pitch of the third terminal electrodes, and the outer periphery surface of the second substrate has an insulating layer formed thereon.
In the above described inventions of (18) to (24), since the insulating layer is formed on the outer periphery surface of the second substrate, a conductive dust, which happens to adhere to the circumference of the second substrate, will be blocked by the insulating layer formed on the outer periphery surface and will not reach the conductive surface. Therefore, no short circuit will take place.
In addition, soldering material or conductive adhesive used to connect the second substrate with a connection object or outside of the substrate, could flow out, but will be blocked by the insulating layer and will not reach the conductive surface. Accordingly, also in this case no short circuit will take place.
(25) A liquid crystal device related to another aspect of the present invention, including a first substrate and a second substrate sandwiching a liquid crystal between them, and first terminal electrodes formed in either of the first substrate and the second substrate, is characterized in that the liquid crystal device further includes a third substrate having second terminal electrodes to be electrically connected to the first terminal electrodes, the third substrate further has third terminal electrodes and wiring electrically connecting the second terminal electrodes with the third terminal electrodes, the wiring has a function of making conversion from the pitch of the second terminal electrodes to the pitch of the third terminal electrodes, and the outer periphery surface of the third substrate has an insulating layer formed thereon.
(26) An electronic appliance related to another aspect of the present invention, including a liquid crystal device, is characterized in that the liquid crystal device has a first substrate and a second substrate, a liquid crystal is sandwiched between the first substrate and the second substrate, and first terminal electrodes are formed in either of the first substrate and the second substrate; the liquid crystal device further has a third substrate having second terminal electrodes to be electrically connected to the first terminal electrodes; the third substrate further has third terminal electrodes and wiring electrically connecting the second terminal electrodes with the third terminal electrodes; the wiring has a function of making conversion from the pitch of the second terminal electrodes to the pitch of the third terminal electrodes; and the outer periphery surface of the third substrate has an insulating layer formed thereon.
In the above described invention of (25) or (26), since the insulating layer is formed on the outer periphery surface of the third substrate, a conductive dust, which happens to adhere to the circumference of the third substrate, will be blocked by the insulating layer formed on the outer periphery surface and will not reach the crystal face. Therefore, no short circuit will take place.
In addition, the soldering material or the conductive adhesive used to connect the third substrate with the first substrate or the second substrate, could flow out, but will be blocked by the insulating layer and will not reach the crystal face. Accordingly, also in this case no short circuit will take place.